Oke Catherine E, Rund Samuel S C, Machani Maxwell G, Sabtiu Abdul Rahim Mohammed, Akuamoah-Boateng Yaw, Afrane Yaw A, Reece Sarah E
Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Charlotte Auerbach Road, Edinburgh, UK.
Center for Research Computing, University of Notre Dame, Notre Dame, IN, 46556, USA.
bioRxiv. 2025 May 1:2025.04.28.650966. doi: 10.1101/2025.04.28.650966.
Vector-borne disease transmission follows daily rhythms because the transmission of pathogens occur at the time of day vectors forage for blood. Insecticide-treated bed nets significantly reduce malaria transmission by interrupting the host seeking behaviour of spp. mosquitoes, yet residual transmission is an increasing problem. Biting when humans are unprotected by bed nets is thought to be a driver of residual transmission, but why mosquitoes are shifting their biting rhythms is poorly understood. We test whether food availability, which mediates activity and foraging rhythms across diverse animal taxa, influences the time of day that mosquitoes bite.
We varied the amount of blood and sucrose that female . received, and used human-mimic traps in a semi-field system to test the hypothesis that low resources cause host seeking to occur at earlier and later times of day.
Nutritional resources determine both the likelihood and time of day that host seeking occurs. Specifically, low-resourced mosquitoes were 2-3 fold more likely to host seek overall, and 5-10 fold more likely to host seek at an earlier time of day than well-resourced mosquitoes, which predominantly sought a host in the second half of the night time.
By driving plasticity in biting time of day, mosquito nutritional condition is an underappreciated contributor to residual malaria transmission. Understanding the drivers of biting time of day variation, and their impacts on parasite development, is crucial for the future success of vector control tools and controlling malaria transmission.
病媒传播疾病的传播呈现出每日节律，因为病原体的传播发生在病媒觅食血液的时间段。经杀虫剂处理的蚊帐通过干扰疟蚊属蚊子寻找宿主的行为，显著降低了疟疾传播，但残余传播仍是一个日益严重的问题。人们认为，在人类未受蚊帐保护时叮咬是残余传播的一个驱动因素，但对于蚊子为何改变其叮咬节律却知之甚少。我们测试了食物可获得性（它调节着不同动物类群的活动和觅食节律）是否会影响蚊子叮咬的时间。
我们改变了雌性疟蚊所获得的血液和蔗糖的量，并在半野外系统中使用模拟人体的诱捕器，以检验低资源导致宿主寻找行为在一天中更早和更晚时间发生的假设。
营养资源决定了宿主寻找行为发生的可能性和时间。具体而言，资源匮乏的蚊子总体上寻找宿主的可能性是资源充足蚊子的2至3倍，并且在一天中较早时间寻找宿主的可能性是资源充足蚊子的5至10倍，而资源充足的蚊子主要在夜间后半段寻找宿主。
通过驱动蚊子每日叮咬时间的可塑性，蚊子的营养状况是残余疟疾传播中一个未得到充分重视的因素。了解每日叮咬时间变化的驱动因素及其对寄生虫发育的影响，对于病媒控制工具未来的成功以及控制疟疾传播至关重要。
